Method of welding



June 30, 1931.

Filed Jan. 27, 1928 INVENTOR GEORG T. J

CKS.

ATTORNEY w m O/\\\. am- 3 N L mm 3 .n. N. r, n. 1. m, fi i ii N. A 3

Patented June 30, 1931 UNITED STATES PATENT OFFICE.

' GEbIBGE '1. J'AOOC'KS, 01' BROOKLYN, NEW YORK, ASSIGNOB, BY KESN'E ASSIGNMENTS, '1'0 ALCO PRODUCTS INCORPORATED, OF NEW YORK,- N. Y A. CORPORATION 01 DELAWARE METHOD OF WELDING Application filed January 27, 1828. Serial No; 249,922.

My invention relates .to a new and improved method of forming autogenous unions and to articles produced by said method, and consists more particularly in a method of joining metals by either electric are or oxyacetylene. It will be described as applied to what is familiarly termed lap welding, and will illustrate various forms thereof.

In the prior art many methods have been used for producing welded lap-j oints but considerable trouble has been experienced therewith especially where such joints have been used in cylindrical units such as tanks, boilers, etc. One of the principal faults has been that the load or pressure strain has been placed upon the weld itself resulting in a rupture at the weld. A further difliculty 1s experienced in such previous methods by reason of the leakage, from even a very slight imperfection in the welding of the single or straight line seams. Also in such previous methods any material within the container can more or less readily attach the weld.

It has heretofore been proposed to lap weld two pieces by perforating one, lapping it over the other which is imperforate and welding the two together through the perforation, filling up the perforation. In service, methods of this character have proven unsatisfactory as the pressure stresses on the two sheets or pieces causes a rupture of the union.

In the present invention I unite metals in the lap fashion so that the resultant weld is free of all tension strain. This is accom- 5 plished by causing the lapping metals to assume the stress by interlocking with each other and utilizing the weld largely as an adhesive seal for the joint.

The interlocking of the metals is produced by perforating one piece and forming projections in the other piece that will register with and enter the perforations of the first piece. With the structure I propose, the projections being formed of the metal itself, cause the strain to be taken on the metal itself and notupon the subsequent weld. This arrangement also facilitates the welding opiaration by predetermining the amount of the In the accompanying drawings, I have illustrated my invention, in which Fig. 1 is a perspective view of the invention as applied to flat surfaces, the weld being omitted;

Fig. 2 is a sectional detail view of a cylindrical oint of the lapped type welded;

Fig. 3 is a detail view showing a method of forming projections on the metal;

Fig. 4 is a sectional detail of a modified form of the joint shown in Fig. 2;

Fig. 5 is a sectional detail showing my invertion as applied to a butt-lap weld joint, an

Fig. 6 is a detail showing a modified form of the method of producing the projections on the metal.

In Figs. 1 and 2, the numeral 10 indicates the inside or lower sheet of metal and 11 the outside sheet of the joint to be welded. Sheet 11 is provided with perforations 12 which may be arranged in any desired manner along the seam. The projections 13 are formedon the inside sheet 10 and are adapted to fit into the perforations 12.

The projections 13 may be formed as shown in Figs. 3 and 6 wherein the perforated sheet 11 may be regarded as a female die member, and 15 the male die member or punch. The projection 13 is formed from the metal of sheet 10 by applying pressure to the die member 15 to force the metal into the perforation 12. It will be noted that the male die member 15 is somewhat smaller than the i perforation so that the metal of sheet 10 as it is being forced into the perforation 12 is notstrained or ruptured on a line connecting the two adjacent edges of the two die members Furthermore, the projection 13 does not extend entirely within the perforation 12 so that the thickness of the metal sheet remains substantially uniform where the sheet is bent, and also substantially the full cross section of the metal 10 is presented across the base of the perforation 12 thus eliminating weakness at this place. In Fig. 3 the full cross section is presented to the perforation whereas in Fig. 6 the upper end of the die 15 is shown as projecting beyond the base line of the perforation. By comparing Figs. 3 and 6 the differences in the male die members and the formation of the projections 13 will be readily perceived.

The jointure between the overlapped margins of the sheets comprises mortise and tenon connections. The mortises being the perforations 12 of the sheet 11, and the tenons being the projections 13 of the sheet 10. The metal of the sheet 10, in the process of forming the tenons is extruded to produce the tenons without rforating them or severing them from the s eet, the tenons being imperforate, unsevered extumescences of the sheet 10. In the form of construction shown in Fig. 3, the tenon is,formed with an abrupt peripheral edge adapted to act as a stop or abutment locking the sheets against movement in a direction cross axial to the tenon, and the mortise is formed with a wall substantially at a right angle to the mortised margin. This form of construction gives the jointure great strength to resist stresses tendmg to separate the sheets in a direction cross axial to the tendns. Such a construction is hi hly advantageous in pressure tanks.

hen completing the seam or joint, the spaces or pits left in the perforation or mortise 12 above the front end of the tenon, are filled with metal 17, which is welded to the edges of the pits and to the front ends of the tenons. The bodies of weld metal 17, serve to hold the sheets against separation in a direction axially of'the tenons, and produce in effect a tenon throughout the entire depth of the mortise. A continuous fillet seam of metal is preferably welded to the end of each sheet and to the face of the adjacent sheet as indicated at 20. ,These continuous fillet seam welds serve as a seal for the joint. The recesses or pits at the rear ends of the tenons formed by the die member 15, are filled with metal 24, which is welded to the wall of the pit. These fillers serve to prevent deformation of the extumescences when heavy stresses are encountered.

A modified form of joint is shown in Fig. 4 wherein the inside sheet 10 is provided with an offset 25 so arranged as to bring the outer surfaces 26 and 27 of the respective sheets on the same line. The joint is completed as described above, except that weld metal is used as indicated at 28 to secure the plates 10 and 11 at the offset 25.

A further modified form is shown in Fig. 5 in which a supplementary plate 31 over the seam-is formed by the abutting plates 10 and 11. The plate 31 contains the perforations 12, and the plates 10 and 11 are provided with projections 13 and 13 which are received in the perforations 12. The ends of the plate 31 are filleted to the plates 10 and 11 as indicatedat 32 while'the unfilled perf forations 12, and the indentations 23 are likewise filled with weld metal. The joint 33 between the plates 10 and 1.1 may or may not be filled with weld or caulked, as desired.

The functioning of my invention may be briefly summarized as the formation of a welded joint by causin projections formed of one of the sheets of t e joint to engage in perforations of another sheet of the joint in such a manner, and the projections being so formed, that any stresses or strains on the joint are borne by the sheets themselves through the medium of the projections. That is to say, any strainstending to spread the union or joint will be taken by the metal along the dotted lines indicated at 30 in the drawings. Hence, I have so arranged the projection as'to present at this point substantially the full strength of the sheet of which it is formed without rupturing or otherwise altering the character of the metal in forming the projection. A further step which is the filling step in my invention is the filling of the spaces above and below the projectionso that the union is'strengthened at this point rather than weakened. i

It will be seen that, if so desired, the projections 13 may be formed before'the sheets are lapped, so that the projections virtually act as dowels in the assembly stage and materially assist such work, predeter'mining the amount of the lap and holding the sheets in position. Also that the perforations could be formed in the lower sheet and the projections in the upper sheet, which is merely the reverse of the arrangement shown in the drawings. 7

It will be understood that various chan es of structural detail may be made without eparting from the scope or spirit of the invention as defined by the appended claims.

I claim: i

1. In a metal article having a fluid jointure comprising overlap ing margins of sheets of metal; a pluralit of spaced mortises in the margin of one of tli e sheets, each mortise being a perforation through said margin; a plurality of tenons projecting fromthe margin of the other sheet and interfitted in the mortises to hold the sheets against relative movement in their respective parallel planes, each of said tenons being disposed inwardly of the edge of the margin of the tenoned sheet, terminating short of the depth of its mortise thereby providing a pit, and being an unsevered extumescence of the tenoned margin; a pit at the rear of each tenon; and a filler of metal in each of the pits, at the front end of the tenons being welded to the peripheral walls of the mortise and to the front end of the tenon.

2. The method of producing a mortise and tenon j ointure between two metal sheets having overlapping margins which comprises orming a mortise extending entirely throu h the margin of one sheet, having its walls su stantiallg perpendicular to the surfaces of the sheets; orming a tenon comprising an improof gamut perforate and unsevered extumeseence on the margin of the other sheet of less length than the mortise and tightl fitting the walls of the mortise, by extru ing metal from said mar 'n directly into the mortise by forcing an imp ement into said tenoned m 'n from the rear thereof concentric with sai mortise so as to form a pit in said mar behind the tenon and concentric therewith, where, by m the deformation of the metal the mortise and tenon are force-fitted together; welding a filler of metal in said pit to aid in maintaining the state of deformation and resultant force-interfitting of the tenon and mortise; and welding a filler of metal in the front end of the tenon in the wall of the mortise to hold the two against relative movement axially of the tenon.

3. The method of producing a mortise and tenon jOli'ltlll? between two mfiltallsheets havm over appm margins w c comprises foming a'morti se extendilig entirely through the margin of one sheet; forming a tenon comprising an imperforate and unsevered ex- 20 tumescence on the margin of the diher sheet of less length than themoitise and tightly fitting the walls of the mortise, by extru metal from such into the mortise o the other mar so as to leave a pit at the 30 rear end of e. tenon; welding a filler of metal to the front end of the tenon and to the wall of the mortise; and welding a filler of metal to the walls of the pit.

In testimony whereof I ailix my signature. GEORGE T. JAOOCKS. 

